P2770

P2770-TRANSMISSION TCC CONTROL CIRCUIT HIGH (DIESEL)





For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


Theory of Operation


The Torque Converter Clutch (TCC) Solenoid is used to engage the TCC which improves fuel economy. The Overdrive Solenoid is used to engage the gear change from third to the Overdrive.


- When Monitored:

Continuously with the ignition on.

- Set Condition:

This DTC will set if the voltage detected on the Torque Converter Clutch Solenoid Control circuit at the ECM is different than the expected voltage. Note: To clear this DTC it is necessary to drive the vehicle at a sustained speed which would allow the TCC and/or Overdrive Clutch to operate







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Checkout (Diesel)



Diagnostic Test


1. CHECK FOR ANY TRANSMISSION CONTROL OR TIPM DTCS

Ignition on, engine not running.

With the scan tool, read Engine DTCs.

Are there any Transmission Control or TIPM DTCs present?

Yes

- Refer to the Transmission category and perform the appropriate symptom(s).

No

- Go To 2



2. CHECK IF THE DTC IS CURRENT

With the scan tool, read Engine DTCs.

Record the Freeze Frame data for the reported DTC.

With the scan tool, erase DTCs.

Turn the ignition off to the lock position.

Using the Freeze Frame data recorded earlier, try to duplicate the conditions in which the DTC originally set.


NOTE: It may be necessary to road test the vehicle to duplicate the original set conditions.

With the scan tool, read Engine DTCs.

Did the DTC reset?

Yes

- Go To 3

No

- Go To 7



3. CHECK THE (T75) TORQUE CONVERTER CLUTCH SOLENOID CONTROL CIRCUIT





Turn the ignition off to the lock position.

Disconnect the Transmission Solenoid Assembly harness connector.

Ignition on, engine not running.

With the scan tool, actuate the TCC Solenoid.

Using a 12-volt test light connected to 12-volts, check the (T75) TCC Solenoid Control circuit in the Transmission Solenoid Assembly harness connector.


NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light cycle on and off and illuminate brightly?

Yes

- Check all internal wiring pertaining to the TCC Solenoid for an open, short, and bent or broken terminals. If no internal wiring problems are found, replace the Transmission Solenoid Assembly.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test

No

- Go To 4



4. CHECK THE (T75) TCC SOLENOID CONTROL CIRCUIT FOR A SHORT TO VOLTAGE





Turn the ignition off to the lock position.

Disconnect the ECM harness connectors.

Ignition on, engine not running.

Measure the voltage of the (T75) TCC Solenoid Control circuit.

Is the voltage above 0.5 volts?

Yes

- Repair the (T75) TCC Solenoid Control circuit for a short to voltage.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test

No

- Go To 5



5. CHECK THE (T75) TCC SOLENOID CONTROL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT





Turn the ignition off to the lock position.

Disconnect the TIPM C10 harness connector.

Measure the resistance between the (T75) TCC Solenoid Control circuit and all other circuits in the Transmission Solenoid Assembly harness connector.

Is the resistance below 5.0 ohms between the (T75) TCC Solenoid Control circuit and any other circuit(s) in the Transmission Solenoid Assembly harness connector?

Yes

- Repair the (T75) TCC Solenoid Control circuit for a short to another circuit(s).
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test

No

- Go To 6



6. ENGINE CONTROL MODULE





Turn the ignition off to the lock position.

Reconnect the ECM harness connectors.

Reconnect the TIPM C10 harness connector.

Turn the ignition on, engine not running.

With the scan tool, actuate the TCC Shift Solenoid.

Using a 12-volt test light connected to 12-volts, check the (T75) TCC Solenoid Control circuit in the Transmission Solenoid Assembly harness connector.

Does the Test Light cycle on and off and illuminate brightly?

Yes

- Go To 7

No

- Using the schematics as a guide, check the Engine Control Module (ECM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the ECM.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test



7. INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set this DTC are not present at this time.

Use the Freeze Frame Data to help duplicate the conditions in which the DTC originally set. Pay particular attention to the DTC set conditions, such as, VSS, MAP, ECT, and Load

Using the schematics as a guide, visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.

Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.

Wiggle the wiring and connectors while checking for any possible open or shorted circuits.

Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test

No

- Test Complete.